Various printing methods that can be used in printing machines are known. One such printing method is inkjet printing or ink-jet printing. In this method, individual droplets of printing ink are ejected from nozzles in print heads and are transferred to a printing material so as to produce a printed image on the printing material. By controlling a plurality of nozzles individually, different printed images can be produced. No set printing forme is used, thus each individual printed product can be designed separately. This allows personalized printed products to be produced and/or, since no printing formes are used, allows small print runs of printed products to be produced at low cost.
The precise alignment of a printed image on the front and back sides of a printing material imprinted on both sides is referred to as register (DIN 16500-2). In multicolor printing, when individual printed images of different colors are combined in precise alignment to form a single image, this is referred to as color registration (DIN 16500-2). In inkjet printing, suitable measures must also be implemented to maintain color registration and/or register.
EP 2 202 081 A1 and JP 2003-063737 A each disclose a printing machine in which the printing machine comprises a first printing unit and a dryer, wherein the first printing unit has a central cylinder with an integral drive motor dedicated to the first central cylinder, and at least one inkjet print head aligned toward an outer cylinder surface of the first central cylinder.
From EP 1 155 987 B1, a roll unwinding device for a web-fed rotary printing machine is known, wherein the roll unwinding device has at least one roll holding device and at least one drive motor, connected to the at least one roll holding device via at least one torque transfer device.
From EP 0 384 988 A2, a roll unwinding device having at least one roll holding device is known.
From DE 39 06 506 C2, a roll unwinding device is known, which has at least one roll holding device and at least one drive motor connected to the at least one roll holding device via at least one torque transfer device.
DE 91 05 487 U1 and EP 0 451 698 A1 each disclose a clamping shaft bearing embodied as a bearing cap.
US 2007/034727 A1, U.S. Pat. No. 5,370,337 A and U.S. Pat. No. 5,255,862 A each disclose a roll unwinding device which has at least one roll holding device and at least one drive motor connected to the at least one roll holding device via at least one torque transfer device, wherein the at least one roll holding device is embodied as a clamping shaft, and wherein the clamping shaft has at least one carrier element, which is connected to the clamping shaft so as to be movable at least in a radial direction with respect to a rotational axis of the clamping shaft, and wherein the roll unwinding device has at least two clamping shaft bearings, at least one of which is connected and/or connectable to the clamping shaft so as to transfer and/or be capable of transferring torque, and wherein the at least one clamping shaft bearing is connected to the at least one drive motor via the at least one torque transfer device so as to transfer and/or be capable of transferring torque.
From EP 0 451 698 A1 a bearing cap of a roll unwinding device is known. A drive for the roll unwinding device and carrier elements are mentioned.
From U.S. Pat. No. 2,082,031 A a roll winding device is known, in which paper is wound onto an expandable core, without inserting a core tube. Drive means and carrier elements are disclosed.
From US 2001 052559 A1 a roll unwinding device is known, which has at least one roll holding device and at least one drive motor connected to the at least one roll holding device via at least one torque transfer device, wherein the at least one roll holding device is embodied as a clamping shaft.
From DE 202 09 571 U1, a roll unwinding device for a packaging machine is known, wherein the roll unwinding device has at least one roll holding device, and wherein at least two roller bearings are arranged at least partially rotatable around a rotational axis, and as pivotable relative to a frame of the roll unwinding device around a pivot axis that is different from the rotational axis.